Eddie's work is amazing. I would also recommend Mark Sorenson at Carne Customs. Unfortunately no matter who you choose, wait times will be long across the board.
+1 for the Hundo case gauge. Does everything you need it to do and you can place an ammo box over top of it, flip it over and with a little shake your ammo is now in the box.
I'm going down the weekend before to shoot the Flagler Cup as well. It should be a good "practice" match before the cup.
I'm just figuring out prone myself. I know it doesn't look pretty watching me get down
I have 6 507c's, 1 508t and a 507k. They have all been 100%. I have a first gen 507c that has over 1,500 rounds of full power 10mm on it with no issues. I'd buy with confidence